A polyrotaxane, which is comprised of a pseudopolyrotaxane, which comprises a linear molecule and cyclic molecules in which the linear molecule is included in cavities of the cyclic molecules in a skewered manner, and capping groups, each of which locates at each end of the pseudopolyrotaxane in order to prevent the dissociation of the cyclic molecules, has characteristics originating from the relative movement of the cyclic molecule(s) along the linear molecule, and is therefore expected to be useful in various applications.
For example, Patent Document 1 provides a polyrotaxane which uses α-cyclodextrins as the cyclic molecule(s) and has a part or all of the hydroxyl groups of the α-cyclodextrins modified with a hydrophobic modifying group. Specifically, Patent Document 1 discloses in the Examples the use of polycaprolactone as the hydrophobic modifying group.
Further, Patent Document 2 discloses a crosslinked polyrotaxane having its solubility in water improved by modifying the hydroxyl groups of α-cyclodextrins as the cyclic molecule(s) with a nonionic group.
More, Patent Document 3 discloses a polyrotaxane-containing wax for coating maintenance, and specifically, the patent document discloses the use of an oleophilic polyrotaxane as a solvent-based coating material and a hydrophilic polyrotaxane as an aqueous coating material. More specifically, Patent Document 3 discloses in the Examples that a product obtained by reacting a stearic acid-modified polyethylene glycol with hexamethylene diisocyanate to obtain a stearic acid-modified polyethylene glycol having isocyanate terminal groups, and reacting this stearic acid-modified polyethylene glycol with the hydroxyl group of α-cyclodextrin which serves as the cyclic molecule of a polyrotaxane, is used as an additive for a wax for coating maintenance.
On the other hand, organic solvents are replacing aqueous solvents for a variety of functional materials, from the viewpoints of reduced burden to the global environment, safety, hygiene and the like. Here, polyrotaxanes, which are expected to be useful in various applications as described above, are also requested to be soluble in water and/or organic solvents, and thus such polyrotaxanes have already been developed as disclosed in Patent Document 2 and the like.    Patent Document 1: WO 2007/026578.    Patent Document 2: WO 2005/080469.    Patent Document 3: WO 2007/106866.